The present invention relates to new and useful improvements in filter assemblies and methods for forming pressure vessel containers for housing the filter assembly.
It is known in the prior art to provide vessels or housings which contain therein a filter element. The filter element may comprise any suitable filter media such as granular absorptive material, or porous sheet material, wound roving or the like disposed in a generally cylindrical form about a central perforated tube member. The filter element is contained within a vessel having a fluid inlet port for receiving a fluid for filtration. The fluid flows radially inward of the filter element with filtrate discharged through the tube member to a discharge port in the vessel housing while solids are retained on the outer surface of the filter media. When the filter element becomes clogged or reaches its solids holding capacity, it is either replaced within the housing or the entire unit is replaced.
In those prior art devices where the filter element is of the replaceable or disposable type the outer vessel housing is usually produced in two sections. The filter element is bonded or welded to the interior of one vessel section and the second vessel section is then welded or adhesively bonded to the first section. The vessel sections are normally injection molded polymer components and are produced in relatively expensive injection molds and injection molding machines.
These filter devices although satisfactory for their intended purposes often encounter manufacturing problems in that the welding or bonding of the vessel sections requires that a joint be designed in such a way as to provide not only a fluid tight seal but have a pressure withstanding capability at least equal to the pressure application of the selected filtration process and in compliance with relevant safety factors. The assembly of the vessel sections is normally accomplished by any number of capital or labor intensive methods such as vibration welding, spin welding, solvent welding, ultrasonic welding, induction welding, hot platen welding, threads and elastomeric seals or adhesive bonding.
It is an object of the present invention to provide a novel filter assembly and pressure vessel for housing the assembly.
Another object is to provide a pressure vessel for housing a filter assembly which is weld free and formed without the use of expensive injection molded polymer components.
A still further object is to provide a novel method and process for forming a pressure vessel closure end and filter element end cap and their interfacial seal in one economical operation.